*{padding: 0;margin: 0;font-size: 14px;font-family: "微软雅黑";}
input{width: 80%;margin: 20px 4%;height: 50px;background: rgba(0,0,0,0.7);border-radius: 10px;padding-left: 40px;color: white;}
body{width: 100%;height: 100%;overflow-x: hidden;overflow-y: auto;}
a{text-decoration: none;color: white;}
#login_bg{width: 100%;height: 100%;position:fixed; left: 0;
    top: 0; z-index: -99;}
#login_bg img{width: 100%;height: 100%;}
#blackmask{width: 100%;height: 100%;background: rgba(0,0,0,0.6);position:fixed;
    left: 0;
    top: 0; z-index: -10;}

#back{width: 100%;height: 50px;}
#back_a{width: 100%;height: 50px; background: rgba(100,100,100,0.8);font-size: 28px;position: absolute;line-height: 50px;}
